diff --git a/gpio.cpp b/gpio.cpp
index 076dee4..a2f1f3e 100644
--- a/gpio.cpp
+++ b/gpio.cpp
@@ -13,6 +13,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
+#include <cassert>
 #include <fcntl.h>
 #include <phosphor-logging/elog.hpp>
 #include <phosphor-logging/elog-errors.hpp>